


pour it all out

by Anonymous



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Anal Sex, Dark Sylvain Jose Gautier, Dead Dove: Do Not Eat, Deepthroating, Derogatory Language, Dubiously Consensual Dating, F/M, Hypnosis, M/M, Man who hypnotized people for sex fails to receive affection and is confused why this upsets him, Mind Control, Multi, Oral Sex, Vaginal Sex
Language: English
Status: Completed
Published: 2021-02-28
Updated: 2021-03-01
Packaged: 2021-03-19 09:41:44
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 2
Words: 6,186
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29748594
Author URL: https://archiveofourown.org/
Summary: Sylvain hypnotizes his hot professor for sex. Dimitri keeps walking in on them, but he can work with that.(Sylvain takes advantage of both Dimitri and Byleth while hooking them up as cover.)
Relationships: Dimitri Alexandre Blaiddyd/My Unit | Byleth, Dimitri Alexandre Blaiddyd/Sylvain Jose Gautier, Dimitri Alexandre Blaiddyd/Sylvain Jose Gautier/My Unit | Byleth, Sylvain Jose Gautier/My Unit | Byleth
Comments: 12
Kudos: 109
Collections: Anonymous, Bottomitri Weekend, Horny Void





	1. Chapter 1

**Author's Note:**

> this is a corruption type deal, so it might not look like much dimivain at first, but the dimivain is coming
> 
> special thank you to my anonymous idea bouncer

The hypnosis spell worked better than Sylvain expected.

He'd tried it on a whim at first, tried to get his girlfriend at the time to admit what she was there for. She'd kept lying, so he'd almost written it off - but later that evening she'd let him fuck her in the ass when she never would before, which was cool. 

And the next time the professor had tried to come for him with a lecture, he'd been able to make her lose her train of thought, send her wandering off in the middle of a sentence.

It was only natural to see how far he could take it.

He doesn't want to cast it on too many people, so continuing with the professor was the obvious challenge. He's been taking it slow, easy... resting a hand on the small of her back when he asked her questions in private, slowly getting bolder so he doesn't suddenly snap her out of it. Last night he'd had her grading papers from his lap, feeling her up over her clothes and leisurely grinding against her ass as she read essays and scrawled down comments. Aside from an occasional distracted gasp or moan, she didn't notice anything off. He's not sure she even remembers he was in her room. It's kind of hilarious.

After feeling her huge tits in his hands, though - the clothed heat of her pussy pressed against his hard-on - he's hungry for more. And maybe this is farther than he meant to go, but...doesn't she owe the world something, by this point? Doesn't the world owe _him_ something?

He had her come to his room this time, sitting blankly on the bed like she's not entirely sure why she's here. The spell's still humming under his skin, giving his words a strange hypnotic weight for the next few hours. 

"Show me your tits," he says, friendly and relaxed, arms crossed over the top of the chair he's straddling. 

Without comment, she pulls off her shirt and opens her bra. Her tits are exactly as great as he'd expected, and he's pondering what to do next - just grope them today, or take a risk and jump straight to titfucking - when the door opens.

You'd think a prince would know how to knock.

Dimitri's mouth is hanging open, a red-hot flush over his face. "Professor - Sylvain - what are you-"

Okay. He's still got the spell on him. He can defuse this.

"Come in and close the door, your Highness." 

Dimitri complies, brow furrowed. "Professor?" he asks uncertainly. Like he just can't believe his dear professor would do this. It's a little insulting, honestly.

But Sylvain can work with it.

"The professor's a grown woman, your Highness. She has needs. Honestly, she wanted to come to you for them - didn't you, Professor?" He wills her to agree, focusing on the spell thrumming through him.

"Yes," Byleth agrees emptily.

"But she was worried you'd think less of her. For needing cock. Didn't want to put another responsibility on your shoulders. I told her it was silly - you'd be happy to give the professor your cock, wouldn't you, Dimitri?"

This is way too easy. Dimitri nods, eyes fixed on the professor's bare tits. 

"Why don't you go show him, Professor? How much you wanted him?"

Haltingly, Byleth stands up, reaches out her hand as she walks to where Dimitri is standing spellbound. (By her? By Sylvain? Who cares.)

It's not seductive enough. "Touch his face," Sylvain says. "Kiss him."

There we go. Dimitri's hands hover uncertainly over Byleth's hips, his noises soft and wanting as she presses her tits to his chest and works her lips against his. 

"Rub his cock," Sylvain says. "You need it."

Dimitri's hands settle fully on the professor's skin, and he lets out needy little whimpers as she cups his clothed erection and starts to caress it.

"There you go," Sylvain says. "Keep going." 

By the time Byleth has Dimitri's fly open, the suspicion has completely dissipated from his face, leaving just a yearning sort of hunger that's the reason this approach is working so well.

"Professor, is this-"

Nope, Dimitri's prudish sensibilities aren't allowed here. "You should let the professor suck your cock, Dimitri."

Dimitri gives a shaky moan, gaping at the professor's mouth as though the thought had never occurred to him. What has he been _wanking to_ all this time? Sylvain knows he has been, has heard him gasp her name through the wall a couple times on still nights when he's studying late. "I - all right. Since she needs it."

"Well? Get to it, Professor."

Byleth falls to her knees immediately, wrapping her lips around the fat head of Dimitri's cock with a clumsiness that might dispel the pretense if Dimitri had any experience at all. 

But he doesn't, and Byleth is a quick learner even when Sylvain doesn't have partial control over her mind. Soon she's bobbing her head on Dimitri's cock, her hand working what she can't swallow as his fingers flex in her hair.

It's the hottest thing Sylvain has ever seen. He's been more cautious until now, but things are going so well...

He walks up to them, unbuttoning his pants. "You're doing great, Dimitri. But I think the professor needs a little more cock to really tide her over."

Dimitri nods, eyes opening for a moment before they flutter shut again.

Sylvain takes his cock in hand and prods at the corner of Byleth's stretched lips. "You can handle two at once, right Professor? You've got a lot of students to be responsible for, after all."

She pulls off Dimitri's cock, frowning for a moment as she considers his next to it. 

He doesn't know if she's finally gotten a sense something is off, or if she's just trying to figure out the mechanics, but he's not going to leave her the opportunity to have a realization. "Go back and forth between them with your mouth. Use both hands," he orders, and her hand wraps compliantly around his shaft.

She looks like such a fucking slut, on her knees with a cock in each hand, sucking on the tip of him with Dimitri's precome smeared over her cheek. 

"Take it deeper," he says, and she shoves her head down onto his cock until she gags.

The control is kind of addictive. 

Just her hand isn't quite as good as her mouth, but watching her suck down Dimitri's dick like it was her idea the whole time more than makes up for it. And Dimitri doesn't last that long anyway - as her lips meet her fingers wrapped around the base of his shaft, he bucks his hips with a surprised gasp, and cum starts to leak from the corner of her mouth.

Eyes wide with surprise, Byleth pulls back, the last spurts of Dimitri's cum landing on her cheek as the load in her mouth dribbles out of her slack lips and onto her tits. That won't do at all. They'll have to work on that.

"Good job, your Highness," Sylvain says. "You gave the professor just what she needed. Professor, tell Dimitri what a good job he did."

Byleth smiles up at Dimitri, like he just aced a training maneuver. "Well done, Dimitri. That was perfect." She pats his thigh, like she's giving him a clap on the shoulder.

Again, she needs to work on the sexy, but in his addled state, it's enough to make Dimitri look absolutely thrilled.

"Now...will you take care of this, Professor?" Sylvain thrusts his still-hard cock towards her face. "It's not nice to leave a job half-finished. Don't you agree, Dimitri? The professor needs to be responsible for her students."

"I - yes, of course," Dimitri says. "I apologize if I was a distraction, Professor."

"You're fine, Dimitri," she says, with another soft crook of her lip. "It's my job to take care of all of you."

Making her service the whole class...there's a thought, but probably more than he wants to bite off. For now, he'll just enjoy having her mouth to himself.

He lets her run her tongue over him for a minute before he takes her head in both hands and thrusts deep into her mouth, pulling back when he feels her start to gag again only to plunge right back in. Her chest makes a strange noise, and he backs off - there's plenty of time left in the school year to train her into deepthroating. 

It's good enough to have her slurping him down, Dimitri watching as though this is completely normal after all the time he's spent chewing out Sylvain for going on _dates_. His balls tighten with the high of it, and he feels his dick harden even further in her mouth. 

"Swallow it," he orders, groaning as the first pulse of cum erupts over her tongue. 

It's that easy. The professor swallows frantically, taking every drop of his load down her throat. 

"There you go. You know, I had some doubts when you were first appointed as a professor, but you're doing a great job taking care of your students. This was a great tutoring session on lance techniques." He pulls out of her mouth, using his thumb to wipe Dimitri's cum off her cheek and dabbing it on her tongue. "Put your shirt on and meet me on the training grounds before dinner. I'd like to try some of those new techniques you taught me and Dimitri in action."

She'd taught them in class this morning, technically, but it should be enough that they both have an explanation for why they were in his room, if anyone asks. 

And he kind of wants to spar with her like this. Even if she kicks his ass, the knowledge she's doing it blissfully unaware she has a stomachful of his cum will be sweet.

* * *

It's kind of fun to watch when Dimitri remembers and doesn't. Sylvain had cast the spell again and had a chat with him about secrecy, and Dimitri had no idea what he was talking about, until he did and earnestly agreed. It seems like they need prompting to remember anything he made them do - although what can qualify as that prompting varies, so he can't get too careless. 

...Admittedly, getting the professor to give him a tit job after class at her own desk could probably qualify as careless. He made some suggestions on the chore roster, though - everyone else should be busy for the next few hours. And just this one memory should be enough to tide him over the next time looking at her face starts to annoy him during class.

"Professor, are you still here? I am afraid that I broke one of the-"

Oh well. At least it's Dimitri again.

Dimitri walks up to the desk, confusion in his voice. "Sylvain, why are you sitting on - oh!" He starts as he gets close enough that Byleth comes into view, kneeling between Sylvain's legs with her tits out. "Do you...need cock again, Professor?"

Wow. This is really just going to take care of itself. 

It's a little annoying that he has to share Byleth's mouth again...but wait. He's the one in control, why does he have to share?

"The professor's helping me out, your Highness," he says, rolling his shoulders. "It's part of her job, to take care of all her students."

"Oh," Dimitri says, blinking. "That must be a great deal of work. Please let me know there's anything I can help you with, Professor." 

Sylvain won't deny he's thought about it, but Dimitri's a friend. He respects him. And turning the crown prince into his plaything is several levels beyond toying around with a no-name professor.

But if the opportunity is going to fall into his lap like this... maybe he'll take it. Just this once. 

"Thank you, Dimitri." Byleth smiles - at him, always at him. "I-"

"-think that's a pretty kind offer, don't you, Professor?" He's not sure what she was going to say, but no point leaving it up to chance. 

"Yes." Byleth nods. "I'd enjoy having your help, Dimitri."

"Take your gloves off, your Highness," Sylvain orders, scooting forward until his balls are hanging over the edge of the desk and spreading his legs wide. "The professor keeps having to deal with my cock, so...how about you suck it this time?"

"Of course," Dimitri says, setting his gauntlets on the desk. "I'd be happy to help."

Byleth scoots off to the side, and then Dimitri is kneeling down in front of his hard cock. He settles his hands on Sylvain's thighs, a bit uncertainly, and leans in to lick a broad stripe up the length of it. 

Sylvain still can't quite believe this is happening.

But then the lips that just a couple weeks ago were yelling at him about going out with girls are opening for his cock, the tongue that's given him a dozen stern lectures on responsibility lapping up his precome like it's a fucking duty.

"Good," he murmurs, brushing Dimitri's bangs back so he can see every bit of his face. "Keep going."

Dimitri's lips slide down his shaft, tongue quivering against the underside as he tries, awkwardly, to suck. 

"Push your lips out and seal them around it," Byleth says in her professor voice - because why wouldn't she, when she sees one of her sweet little students having trouble with something, when Sylvain's got it in her head that sucking his cock is as much a part of her job as teaching them lancework? It's so perfect he has to bite down a laugh.

With the professor's guidance, Dimitri gets the sucking motion down, and Sylvain groans, letting his hips rock forward just a bit into Dimitri's mouth. 

"You're doing wonderfully," Byleth praises. 

The sureness in her tone makes him wonder just how many of the skills she's been instructing them on with such confidence she picked up a few nights earlier herself - but then Dimitri's tongue slides under his foreskin, and he decides he has more important things to think about right now.

 _Holy shit_.

Framing it as helping out the professor was a great call. Dimitri is so fucking eager to please - lapping frantically, sucking Sylvain's cock down deep enough that the back of his throat keeps convulsing.

"Relax your throat." Sylvain doesn't really intend it as an order, but it works immediately - Dimitri's throat goes slack and accommodating where he was gagging just a moment ago. Fuck.

"Take me deeper," he says, testing, and suddenly Dimitri can do it, his body all too happy to let Sylvain's cock slide deeper until the head's pressed against the back of his throat. Sylvain can feel him swallow against it, his tongue still working diligently over the underside. "Good."

Dimitri looks - happy. Eyes proud, like he's excited he could get past his body's reflexes to be so helpful. 

To the professor.

There's this part of Sylvain that's never happy, that can never get _enough_ , even when he's got the crown prince choking on his cock and his hot professor waiting on the sidelines ready to do whatever he wants. 

"Professor, you should be licking my balls." She looks too respectable right now, face placid and responsible as she stands ready to mentor her student on cocksucking. She obeys, of course she obeys, she's so far gone he's not sure what he'd have to do to break the spell anymore - and as she maneuvers herself so she can get at his ballsack without disrupting Dimitri's important work, Sylvain taps Dimitri's cheek and gives another order, just to see what he'll do.

"Deeper."

Dimitri strains forward, trying to find an angle that will let him shove his head further onto Sylvain's cock. The head catches on the bend of his throat, and he keeps pushing. His throat is still so pliant and accommodating, like his entire body's agreed that its most important priority is to service Sylvain's cock, and Sylvain groans in disbelief as he feels the head of his cock penetrate Dimitri's esophagus. Dimitri doesn't even pause, just keeps going until his nose is mashed into Sylvain's abdomen, the end of Sylvain's cock stuffed down his throat.

His throat is so fucking _tight_.

"Shit, that's good." Sylvain ruffles Dimitri's hair, panting. "Leave room for the professor though, okay?"

As soon as Dimitri shifts his torso, one of his nuts is sucked into warm, wet heat. The professor cradles it carefully between her lips, running her tongue over it in the way he can never get girls to do, normally. Too fussed about his hairy ballsack, or the musk, or _it's kind of degrading, isn't it?_ You'd think they'd be more willing to commit for the cause, but maybe they can see through him, that he's not going to give them what they want.

Taking Dimitri's head in both hands, Sylvain pulls him back until just the head is resting on his tongue, purely to watch how much of his cock was just buried in the prince's mouth. "Breathe," he orders, suddenly unsure how long Dimitri would have stayed down there if he hadn't interfered. Would he have gone until he passed out on it, just because Sylvain didn't tell him to stop? He'll have to keep a closer eye on them. 

Maybe he should drive for now. He pulls Dimitri towards him again, further than he's ever pulled a girl, moaning in ecstasy as his cock slides back down into the tight heat of Dimitri's throat. 

"Shit," he pants - pulling him back off again, starting to build a rhythm as he fucks into Dimitri's throat again and again. "You look so good like this."

Both of them do - tears and saliva dampening Dimitri's face as he determinedly lets Sylvain use his mouth, Byleth kneeling under her own desk straining to get at his nuts around Dimitri's chin. 

And they thought they were above this. Who would have thought the crown prince had such a tight little cunt of a throat?

Normally he has to choose between sensations, but with his prick buried in Dimitri's esophagus and Byleth's mouth enveloping whatever parts of his ballsack she can reach, everything feels hot, wet, amazing. He deserves this, he reminds himself. He deserves this. 

He can feel his balls starting to pull up, Byleth's tongue straining to chase after him. He pulls Dimitri all the way down, nose mashed into his pubes, and groans as the pressure building up inside him explodes, the base of his cock pulsing on Dimitri's tongue as the pair of them wring his load out of him. The professor's still lapping at his balls as they pump his cum so far down Dimitri's throat that Dimitri doesn't even have to swallow.

 _Fuck_. 

It's the best nut of his life.

Sylvain pulls out slowly, sighing in loss as his cock leaves the paradise of Dimitri's mouth for the comparatively cool air of the classroom. Byleth's still licking gently, and he regretfully pushes her away as well, before wiping both of their faces clean with a handkerchief.

"You should heal Dimitri's throat," he tells Byleth. "And put your shirt back on."

"Of course," Byleth says, a spell soon glowing on her hands. "Thank you for the help, Dimitri."

He smiles, drinking in her praise. "I'm happy to assist whenever you need me," he rasps. 

Yep, he definitely needs that healing.

As Byleth heals his highness's throat, Sylvain tucks his cock back into his pants, contemplating where he should take things from here. Obvious things first - he should try that "relax" trick on Byleth. He's not going to be able to play around with her forever...might as well take full advantage while he can, before he graduates and gets trapped in the life his father always wanted for him. 

And if Dimitri happens to make another offer...

Who's he to turn it down?


	2. Chapter 2

Everyone's so _happy_ with him lately.

Dimitri complimented him on his restraint recently. How little he's been cavorting with women and running off to town. Can't even remember that he's taken six of Sylvain's loads down his throat in the last three weeks, that Sylvain's blown twice again as many in or on his darling professor in that time. 

It's addictive. Knowing what happened, watching them have no idea. Dimitri looking like butter wouldn't melt in his mouth when three days ago he rimmed the professor for an hour just so Sylvain could stuff his cock into her ass. The professor congratulating his quick progress on white magic when he's only learning it so he can ream her throat.

He hasn't touched her cunt, yet. More to worry about with that. 

And speaking of worrying, Dedue is starting to get suspicious. Sylvain needs a better excuse for them than extra tutoring sessions. Preferably something they could do together...

Oh, perfect.

* * *

Convincing them they were having a secret affair was a stroke of genius, honestly. Now he doesn't have to worry so much about leaving marks, or cumming somewhere they'll find it later - even once they come to, they'll think it's their secret to hide.

The only problem is that he didn't expect quite how _well_ it would work. It's just a lie, he didn't think it would bleed over into their behavior while lucid. But those special smiles that the professor only gives to Dimitri - or at least doesn't give to _him_ \- are getting warmer and warmer, and he keeps finding them having tea together, or private conversations. Yesterday he went to Byleth's room and found Dimitri already there, cuddled against her side as they reviewed a lesson plan, both of them sneaking kisses between pages.

Something about it pisses him off.

This is supposed to be her comeuppance, and yet she seems _happier_. He's aware, on some level, that it's making him crueler, but can't really bring himself to care.

It's now easy to give her a reason to start taking contraceptives, though. He didn't go this far just to use skins - the first time he takes her cunt, it's going to be raw.

* * *

Byleth's cunt is amazingly tight. He wonders if she was a virgin.

He's got her on her back on her bed, holding her knees to her chest to offer up her pussy for his use. It's been slow going, but now he's sinking balls-deep on each thrust, her tits bouncing each time his hips hit her ass. Her face is more impassive than he'd like, but her cunt is plenty responsive - she came on his dick earlier while he was fondling her clit to get her wetter, her little hole fluttering around him as a flash of vulnerability crossed her face.

Right on schedule, Dimitri knocks on the door, and Sylvain pulls out, leaving Byleth's cunt fucked-loose and slick. Dimitri wouldn't know the difference, even if he were in his right mind. 

He'd meant to leave himself time to come on Byleth's face before Dimitri arrived - it would've been funny to watch them fail to notice - but he got a little too lost in the feel of his cock stretching her open, leisurely plumbing what felt like uncharted territory.

"Put on your shorts, open the door, and fuck Dimitri," he tells her. "I'm not here. I haven't been here all day."

He'll figure out what to do with this hard-on later. He wants them to remember this, but as long as he doesn't get _too_ in the way, their minds should be able to erase him from the scene. He's been testing.

Byleth gets up, puts on her shorts, and opens the door. 

"Hello Professor. Is this...still a good time?"

Byleth nods, stepping back so he can close the door behind him. The moment it's locked she wraps her arms around his neck and pulls him down in a kiss - maybe he should've added another step between "open the door" and "fuck Dimitri" - but it comes off naturally, like she was excited. Dimitri's arms come down to embrace her and they stumble backwards to the bed, ending with her in his lap.

They keep kissing, hands dipping under clothes, happy little gasps between each others' mouths like they really are an innocent young couple in the midst of their first time.

"I confess, I still cannot believe we're doing this," Dimitri laughs softly into her neck. "It would be simpler to wait until I graduate, yet I find that I can't."

"I need you." Byleth sounds like she believes it. 

He'd resigned himself to her dull tone and glassy eyes when he's got her under, but she's started looking _alive_ when she looks at Dimitri. It's not fair. This isn't real. He's ordering them to do this, why do they keep acting like it's real for each other but not for him? 

Dimitri's hand slides down into her shorts. "You're so wet for me already," he gasps, and Sylvain bites down a snigger.

He doesn't know why he was expecting it to be fast and rough. They take their time, running their hands over each other, kissing each other's skin. Dimitri goes crazy for Byleth's tits, shoving his face in there like he hasn't seen them a dozen times already. If she didn't bathe this morning they might still smell like Sylvain's balls from when he sat on her face last night and fucked them. Dimitri was there, held them together for it, caught Sylvain's load in his mouth.

It's a little boring to watch. Or...not boring, maybe, but there's something about it he's not enjoying. He wants to see the professor get _used_ , get her comeuppance, and here's Dimitri looking at her like she hung the fucking moon. Here she is looking back like she set this up on her own. Like Sylvain's not even here at all - no, that's right, that's what he asked for. Not _supposed_ to be here.

When Dimitri pushes his cock in, though, and Sylvain knows it only went in that easy because Byleth's still loose from taking his dick? That's good.

It's enough to perk his cock back up, but the position they ended up in - Byleth on her back and their faces within kissing distance, her legs wrapped around Dimitri's waist pulling him in towards her body with every thrust - doesn't give him much to do with it. They're too focused on the kissing for him to stick his cock between their faces. He walks to the foot of the bed and considers - no, he doesn't have good access to Byleth's ass.

"You feel _wonderful_ ," Dimitri moans. He spreads his knees apart for better leverage, and Sylvain catches an inviting flash of pink hole.

It's always seemed too far. The professor is the main person he wanted to teach a lesson - Dimitri could use a taste of it, sure, but Sylvain doesn't have quite the same desire to see him laid low. 

But watching them is still pissing him off, and honestly, he doesn't remember what he was hung up about. It's the only hole available right now. It'll be funny. Maybe he can find the stick up Dimitri's ass. 

Grabbing a vial of oil off Byleth's shelf and drizzling some onto his fingers, he slides them down the cleft of Dimitri's ass and presses in against that wrinkled pink hole. 

Dimitri starts a little, and Sylvain's quick to remind them - "You don't notice me. I'm not here." He presses the tip of one finger past the rim of Dimitri's ass, into plush and wet and soft, and his cock jerks against his abdomen.

As his highness unsteadily thrusts into the professor like an incompetent virgin, Sylvain slowly fingers open his royal ass, until Dimitri's hole is pliant and shiny with oil, readily swallowing two of his fingers to the last knuckle.

Sylvain pours some more oil into his palm and climbs onto the bed behind them, giving his own dick a couple greedy pumps as he runs a hand down Dimitri's thigh to relax him.

"I love you," Dimitri gasps.

He's talking to the professor.

And that shouldn't piss Sylvain off, but he grabs Dimitri's hips a little more roughly than he needs to, lines up the thick head of his cock and drives home in a single thrust that has Dimitri crying out against the professor's mouth. 

Until this point, Sylvain can honestly say that he hasn't spent all that much time thinking about his prince's ass. His face, his mouth, even his dick, sure - but before today, Sylvain had never given the specifics of Dimitri's ass all that much consideration. Now that he's buried balls-deep inside it, though, he can say pretty confidently that it looks great split open on his cock. His cheeks are muscular, his rim a cute pink now flushed darker where it's spread around Sylvain's prick, and the few curly blond hairs scattered around don't really detract from the overall aesthetic. 

He starts to thrust.

He doesn't bother being shy about it - if they can fail to notice him back here fucking Dimitri's ass, the speed isn't really going to change things.

With Sylvain's cock pumping into his ass, Dimitri has a guide for his rhythm, and soon the pace of his hips fucking into Byleth gets smoother as he matches Sylvain's thrusts. 

Settling his hands on Dimitri's ass, Sylvain adjusts the angle of Dimitri's hips so he can get deeper - and Byleth starts to moan softly with each thrust, reaching up to wrap her arms around Dimitri's back as the sound of his cock humping into her gets wetter.

Good thing for them he's here, or this would have been a disaster.

He's being rewarded plenty though - Dimitri's hole is hot and tight, welcoming his dick in on every stroke. Every time Sylvain really rams it into him, he whimpers, and Byleth kisses him soothingly like she thinks it's something she's doing, somehow. 

"Dimitri - I'm - mm!" 

Byleth shudders underneath them, and Dimitri lets out a long groan. 

"Yeah," Sylvain grunts, driving into him in short, sharp thrusts. "It's good, isn't it? Her little cunt quivering around your dick? I know just what that feels like."

Sylvain's pretty sure he's hitting something good, as he pumps into Dimitri's hole - Dimitri's cries are growing increasingly more ragged, and it's really not fair that he's not getting any credit as they start to bleed into the professor's name. 

"Ah...oh...- _Professor!_ "

Sylvain feels Dimitri's balls draw up where his are dangling over them. Dimitri's body tenses, and he mashes his mouth into Byleth's, his knees trembling and his ass pulsing around Sylvain's prick. He's got to be filling her up. Good - now if Sylvain gets her pregnant by some freak accident, she'll have a reason. 

As he keeps driving his prick into Dimitri's quivering ass, he swears that the twitching of Dimitri's balls is lining up with his thrusts, like Sylvain is fucking the cum right out of him. It just keeps going, Dimitri moaning desperately into Byleth's mouth with each pulse of his balls as Sylvain drills his ass. Byleth is gasping, like she can feel Dimitri filling her up. 

“It’s so hot,” she mumbles into Dimitri's mouth.

“If you keep squeezing like that I—”

Oh, she’s squeezing his dick too? Sylvain almost feels a little sorry for him. In a “lucky bastard” sort of way, not a way that makes him want to stop pounding Dimitri’s ass.

By the end of his orgasm Dimitri’s incoherent, shuddering against the professor and babbling a string of a stream of moans and syllables that might’ve been supposed to be her name. 

“Cuddle,” Sylvain directs them, and Dimitri collapses forward onto Byleth, her arms coming up to hold him.

Sylvain keeps going.

Now that he doesn’t have to worry about shoving Dimitri too hard into Byleth, he braces his legs for more leverage and grabs Dimitri’s hips in both hands, drawing his cock back until the head is pulling at Dimitri’s rim before slamming it back in. Dimitri cries out—poor guy’s probably a little oversensitive—and the professor pets at him soothingly, even if she's not sure why she's doing it.

As Dimitri nuzzles into the professor’s hair, Sylvain picks up speed. The bed starts shaking with the force of his thrusts as he hammers into Dimitri's lax body. Wet sounds fill the air from his balls smacking into Dimitri's taint and Dimitri's softening cock getting jostled inside the cunt it just creamed. By the time Sylvain starts getting close, Dimitri's making broken little noises into Byleth's neck, hiccupy little sobs in time with Sylvain ploughing his tight hole.

Suddenly, Dimitri's body seizes up with a disbelieving moan. "I'm sorry," he gasps, "I - I think I'm coming again. I don't know-" He catches Byleth's lips with his, kissing her fervently as his balls twitch weakly in another orgasm.

He was really just dying to get fucked up the ass, huh?

Sylvain chuckles under his breath, still pounding away as Dimitri trembles through his _mysterious_ orgasm. He wonders if Dimitri will try to discreetly ask him about it, or just assume Byleth's cunt is that good.

Soon he can feel his own cock start to swell, pressure building in his groin. Sylvain buries every last inch of his cock in Dimitri's ass, pressing his hips forward to get as deep as he can. 

"Fuck...yes...take it-" he groans, throwing his head back as his balls pump pulse after pulse of cum deep into Dimitri's ass. It just keeps pouring out of him, like he's filling Dimitri's ass with not only the load he intended for Byleth, but a whole extra load he built up while fucking it. The pleasure washes over his body, leaves him fuzzy-headed and feeling _fucking amazing_. 

Even after he's fully emptied his balls, he gives himself a minute to luxuriate in it before he finally pulls out. Dimitri's hole looks wrecked - loose and wet, a trickle of jizz leaking down to his balls and more threatening to drip free from the slack rim. 

He gives Dimitri's ass a friendly slap and climbs off the bed, stretching. 

Dimitri cuddles the professor for a while longer, long enough for Sylvain to wipe his messy cock clean on one of her discarded shirts and get himself looking presentable. When they finally pull apart, the professor carefully stands up and holds a towel between her legs, but Dimitri just sits on the edge of her bed, his ass undoubtedly leaking jizz out onto the sheets. Because he has no reason to think he shouldn't. 

"That was wonderful," he says, taking the professor's hand and kissing her knuckles. "I hope it was good for you as well?"

"It was." She smiles at him.

"I...suppose we can't stay alone together much longer for now, can we?" Dimitri sighs. The professor offers him her towel, and he wipes off his cock and puts on his underwear, a trail of cum still running down his inner thigh.

The professor nods. "You should have dinner with me again, though," she says, and Dimitri's face lights up.

At this rate, he's going to propose by the time they graduate. Sylvain doesn't know why the thought makes him angry - it's the opposite of what he was going for, he guesses. He was trying to humiliate the professor and instead he might accidentally make her a queen. 

That empty, sinking feeling he hates is starting to creep up on him. Normally this is when he'd cheat on his girlfriend, but he doesn't have a girlfriend to cheat on.

At the back of his mind, though, there's a stray spiteful thought. If she did become queen...nobody says he has to stop.

The thought brings the rush he was looking for, and he chases it. He imagines the professor in royal regalia, bent over a balcony at a ball with her skirts hiked up around her waist as he rails her between dances. King Dimitri's crown getting knocked off kilter as Sylvain fucks his face. Visiting to congratulate the royal couple on their impending heir and convincing Dimitri that his wife needs her cunt double-stuffed to help her get ready. Fucking Dimitri over the throne in his own audience chamber.

By the time they've dressed again, the emptiness has receded, and he's feeling confident as ever. Satisfied. As good as he can feel when every day solidifies his long-standing suspicion that he's no better than Miklan, just luckier. 

But then, that's probably true of a lot of people. They just don't have the tools that he does.

He follows Dimitri and the professor out of her room, trails after Dimitri as he heads towards the training grounds. When he sees Sylvain heading in after him, Dimitri lights up, waves him over to the rack of training lances with a challenging grin. 

Sylvain isn't above exploiting his sore ass to beat him. 

And as Sylvain helps him up off the ground, Dimitri smiles at him. Praises him on how diligently he's been training.

Yeah, Sylvain nods to himself. This spell is great.

**Notes for the Chapter:**

> Sylvain: *hypnotizes people for sex when he actually wants affection, orders them to act like they're dating and he's not there*  
> Dimitri and Byleth: *act like they're dating and Sylvain's not there*  
> Sylvain: >:(


End file.
